Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756267AbYBTOw5 (ORCPT ); Wed, 20 Feb 2008 09:52:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750987AbYBTOwq (ORCPT ); Wed, 20 Feb 2008 09:52:46 -0500 Received: from e1.ny.us.ibm.com ([32.97.182.141]:37744 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750915AbYBTOwp (ORCPT ); Wed, 20 Feb 2008 09:52:45 -0500 Subject: Re: [PATCH] hugetlb: ensure we do not reference a surplus page after handing it to buddy From: Adam Litke To: Andrew Morton Cc: Andy Whitcroft , Nishanth Aravamudan , William Irwin , linux-mm@kvack.org, linux-kernel@vger.kernel.org In-Reply-To: <20080219153037.ec336fd2.akpm@linux-foundation.org> References: <1203445688.0@pinky> <1203446512.11987.36.camel@localhost.localdomain> <20080219153037.ec336fd2.akpm@linux-foundation.org> Content-Type: text/plain Organization: IBM Date: Wed, 20 Feb 2008 08:59:34 -0600 Message-Id: <1203519574.11987.67.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1291 Lines: 33 On Tue, 2008-02-19 at 15:30 -0800, Andrew Morton wrote: > On Tue, 19 Feb 2008 12:41:51 -0600 Adam Litke wrote: > > > Indeed. I'll take credit for this thinko... > > > > On Tue, 2008-02-19 at 18:28 +0000, Andy Whitcroft wrote: > > > When we free a page via free_huge_page and we detect that we are in > > > surplus the page will be returned to the buddy. After this we no longer > > > own the page. However at the end free_huge_page we clear out our mapping > > > pointer from page private. Even where the page is not a surplus we > > > free the page to the hugepage pool, drop the pool locks and then clear > > > page private. In either case the page may have been reallocated. BAD. > > > > > > Make sure we clear out page private before we free the page. > > > > > > Signed-off-by: Andy Whitcroft > > > > Acked-by: Adam Litke > > Was I right to assume that this is also needed in 2.6.24.x? Yep. Thanks Andrew. -- Adam Litke - (agl at us.ibm.com) IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/